1. Technical Field of the Invention
This invention relates to diamidopolyamines such as an diamidotriamines. More particularly, this invention relates to novel diamidopolyamines derived from polyoxyalkylene polyamines and glutamic acid. Still more particularly, this invention relates to novel diamidopolyamines prepared by reacting at least about 2 mole equivalents of a polyoxyalkylene diamine or polyoxyalkylene triamine with glutamic acid to thereby couple each of the carboxyl groups of the glutamic acid to an amine group by the formation of an amide linkage therebetween. The reaction is preferably conducted at autogenous pressure at a temperature within the range of about 150.degree. to about 250.degree. C.
The diamidopolyamines of the present invention can be used as raw materials for a wide variety of purposes such as, for example, as chain extenders for epoxy resins, curing agents for epoxy resins, as raw materials for the manufacture of polyureas, thickening agents, etc. The products may also be used as raw materials for the preparation of fuel and lubricant additives, for textile and fiber treating agents, for the preparation of adhesives, for use in the manufacture of polyureas, for use in encapsulation and molding applications, etc.
2. Prior Art
It is known, as exemplified by Yeakey U.S. Pat. No. 3,654,370 to prepare polyoxyalkylene polyamines by the reductive amination of a polyoxyalkylene polyol. The reductive amination is conducted catalytically in the presence of hydrogen and ammonia and an appropriate reductive amination catalyst, such as a nickel, copper and chromia catalyst. The polyoxyalkylene polyamines that are prepared in this fashion are stable articles of commerce having a wide variety of uses such as those mentioned above. In particular, they have found utility as curing agents for epoxy resins, as plasticizers, as cross linking agents and binders for textiles, and as intermediates in the preparation of polyureas. In general, polyoxyalkylene polyamines having molecular weights ranging from about 200 to about 5,000 can be prepared by the Yeakey process.
Kwang. U.S. Pat. No. 3,257,342 is directed to epoxy resins that are cured with a polyamidodiamine prepared by reacting about two molar equivalents of a polyoxyalkylenediamine with an aliphatic dicarboxylic acid.
Klein U.S. Pat. No. 4,133,803 is directed to the preparation of novel thermoplastic adhesive compositions having melting points between 20.degree. and 180.degree. C. prepared by reacting a polyoxypropylene diamine or triamine with an aliphatic or aromatic dicarboxylic acid, ester or anhydride thereof. In his working examples, Klein used approximately equimolar amounts of carboxylic acid and polyamine. However, he states that the molar ratio of the polyoxypropylene diamine or triamine to the dicarboxylic acid may range from about 0.25:1 to about 4.0:1. The thermoplastic adhesives of Klein are made by reacting the polyoxypropylene diamine or triamine with the dicarboxylic acid at about 175.degree. to about 275.degree. C. for about 1 to 12 hours.
The preparation of thermoplastic adhesives is disclosed in Schulze U.S. Pat. No. 4,119,615. The adhesives are prepared by a two-step process. In the first step, about 1 to 4 moles of oxalic acid is reacted with a polyoxyalkylene diamine or triamine, the preferred ratio being a mole ratio of about 1 to 2 moles of oxalic acid per mole of polyoxyalkylene diamine or triamine. This results in the formation of a so-called liquid prepolymer which is then reacted with an alkylene diamine such as ethylene diamine which contain 2 to 18 carbon atoms to provide the resinous polyoxyamide thermoplastic adhesive composition.
Mains et al. U.S. Pat. No. 4,062,819 is directed to polyamide polyblends wherein one component is a high molecular weight thermoplastic polyamide and the other is a minor amount of a polyamide derived from a high molecular weight dibasic acid. The second component is prepared by reacting a dicarboxylic acid such as "dimer acids" with an aliphatic alkylene diamine such as ethylene diamine.
Rieder U.S. Pat. No. 4,239,635 (reissued as U.S. Pat. No. Re.30,885) is directed to lubricants modified by the inclusion of diamides. The diamides are carboxylic acid terminated reaction products of an excess of a dicarboxylic acid with a polyoxyalkylene diamine.
Rasmussen U.S. Pat. No. 4,218,351 discloses impact resistant thermoplastic polyamides which are suitable for use as hot melt adhesives and which contain, as a component, a minor amount of an amorphous amide-forming oligomer which is described as a polyoxyalkylene diamine having a number average molecular weight in the range of about 900 to about 5000.
Mitchell, et al. U.S. Pat. No. 4,062,820 discloses copolyamides derived from a mixture of a polymeric fatty acid and a short chain dibasic acid with a mixture of amines composed of a polyoxyalkylene diamine and a short chain diamine such as ethylenediamine.
Rieder U.S. Pat. No. 4,239,635 is directed to aqueous metal working fluids containing a carboxylic acid group terminated polyoxyalkylene diamine or the alkali metal, ammonium or organic amine salts of the diamides. The diamide is prepared by reacting a dicarboxylic acid with a polyoxyalkylenediamine in a 2:1 mole ratio.
Chang U.S. Pat. No. 4,588,783 relates to heat curable compositions containing polyhydroxyethyl carbonates which are prepared by reacting an amidoamine with an organic carbonate. The amidoamines are prepared by reacting a polyester with an equivalent excess of a polyamine, for example, by reacting two moles of isophorone diamine with one mole of dimethylcyclohexane dicarboxylate.
Bently U.S. Pat. No. 4,751,255 is directed to polymeric polyamines prepared by reacting a polycarboxylic acid or an ester thereof with a stoichiometric excess of a polyamine having terminal aminopropoxy groups to provide polymeric polyamines containing 2 to 4 primary amine groups per molecule.
In Kirk-Othmer, 2nd Edition, Volumne 2, at pages 207-208 it is reported that glutamic acid reversibly dehydrates to pyroglutamic acid, the equilibrium point and rate of reaction varying with pH.